1. Field of the Invention
The present invention relates to a viewing apparatus which includes a viewing optical system (e.g., a viewing optical system of a telescope or a binocular) and a photographing optical system for photographing an object viewed through the viewing optical system, wherein a distant object can be viewed visually and recorded as image data at the same time with the viewing apparatus.
2. Description of the Prior Art
Telescopes and binoculars are known as viewing apparatuses for viewing distant objects. However, such conventional viewing apparatuses do not have a function of recording object images which are viewed therethrough. Although there have been various proposals of combining a viewing apparatus such as a telescope or a binocular with a photographing system (e.g., a camera) to achieve such an image recording function, none of these proposals are practical for ordinary users.
When viewing a distant object through a viewing apparatus such as a telescope or a binocular, the user needs to perform a focusing operation to focus the viewing apparatus on the distant object to obtain a sharp image thereof. Likewise, when taking a picture of a distant object with a camera, the user needs to perform a focusing operation to focus the camera on the distant object to obtain a sharp image thereof. Accordingly, in the case where the viewing apparatus is combined with the camera, only a single focusing operation needs to be performed to take a picture of the distant object if the focusing mechanism of the viewing apparatus is interconnected with the focusing mechanism of the camera. This makes it possible for the user to concentrate on performing the focusing operation of the viewing apparatus, without being bothered by the focusing operation of the camera.
However, if the focusing mechanism of the viewing apparatus is simply interconnected with the focusing mechanism of the camera, the camera cannot be sharply focused on the object to obtain a sharp image thereof since vision varies between individuals. Namely, if different users having different visions perform a focusing operation, the focal point varies between the different users. Therefore, since vision varies greatly between individuals, the focal point also varies greatly between individuals as photographing with a camera. Consequently, a sharp, in-focus pictures can be difficult to obtain depending upon the user.
A method of preventing such a problem is known in the art. According to this known method, an indicia is disposed at a reference focusing point in an optical path of the viewing apparatus so that an image of the indicia can be seen in a field of view of the viewing apparatus, while the diopter of the viewing apparatus is corrected to correspond to the vision of an individual user with any known device such as a diopter correcting mechanism while the user is looking at the image of the indicia in the field of view.
To indicate an image of the indicia in the field of view of the viewing apparatus, a transparent member on which the indicia is imprinted needs to be disposed at the position where an object image is formed through the objective optical system of the viewing apparatus or a translucent member on which the indicia is imprinted needs to be disposed in an optical path of the viewing apparatus so that the object image and the image of the indicia are seen simultaneously through the viewing apparatus. However, scratches and/or dust on the transparent member are visible, and thus, distractive to the user""s eyes in the case where the indicia is disposed at the position where an object image is formed through the objective optical system, and the transparent member deteriorates the optical performance of the viewing apparatus in the case where a translucent member is utilized. Moreover, the indicia is always seen in the field of view of the viewing apparatus, and hence, obstructs the view.
The present invention provides a viewing apparatus having both a viewing optical system such as a telescope or a binocular for viewing distant objects and a photographing system for photographing images of the distant objects, wherein the photographing system can photograph sharp and in-focus images of distant objects regardless of variations in vision between individual users, and wherein an image of the indicia is indicated in the field of view of the viewing optical system only when a diopter correcting operation is performed so that the image of the indicia does not obstruct the view.
As an aspect of the invention, a viewing apparatus is provided, including, a viewing optical system having a positive objective optical system and a positive eyepiece optical system, an image of an object formed through the positive objective optical system and viewed through the positive eyepiece optical system; a photographing optical system, provided independently from the viewing optical system, for photographing the object image viewed through the positive eyepiece optical system; a first focusing mechanism for changing an image focal point of the object image formed through the positive objective optical system of the viewing optical system; a second focusing mechanism for changing an image focal point of an object image formed through the photographing optical system; an association mechanism which interconnects the first focusing mechanism with the second focusing mechanism; and an indicia indication optical system for selectively indicating the object image and an indicia image in a field of view viewing through the positive eyepiece optical system.
It is desirable for the indicia indication optical system to include a mask member having an indicia for forming the indicia image visually in the field of view, wherein a position of the mask member and a position where the object image formed through the positive objective optical system is in an in-focus state are optically conjugate in a state wherein the indicia image is indicated in the field of view via the indicia indication optical system.
It is desirable for the indicia indication optical system to include a light shield device which isolates a portion of the viewing optical system which is positioned in front of the indicia indication optical system in an optical axis direction of the viewing optical system from the remaining part of the viewing optical system.
The light shield member can be a movable reflection member which can be inserted into and retracted from an optical path of the viewing optical system, the indicia image being indicated in the optical path when the movable reflection member is in the optical path of the viewing optical system.
It is desirable for the movable reflection member to isolate a portion of the viewing optical system which is positioned in front of the movable reflection member in an optical axis direction of the viewing optical system from a remaining portion of the viewing optical system when inserted into the optical path of the viewing optical system.
It is desirable for the movable reflection member to be a total reflection mirror that totally reflects light incident thereon.
It is desirable for the viewing apparatus to further include a release mechanism for releasing the association mechanism so that the first focusing mechanism and the second focusing mechanism can operate independently from each other.
The viewing optical system can serve as a telescope optical system.
As another aspect of the invention, a viewing apparatus is provided, including a pair of viewing optical systems each having a positive objective optical system and a positive eyepiece optical system, an image of an object formed through the positive objective optical system and viewed through the positive eyepiece optical system; a photographing optical system, provided independently from the pair of viewing optical systems, for photographing the object image viewed through the positive eyepiece optical system; a first focusing mechanism for changing an image focal point of the object image formed through the positive objective optical system of the viewing optical system; a second focusing mechanism for changing an image focal point of an object image formed through the photographing optical system; an association mechanism which interconnects the first focusing mechanism with the second focusing mechanism; and an indicia indication optical system for selectively indicating the object image and an indicia image in a field of view viewed through the positive eyepiece optical system.
It is desirable for the optical axis of the photographing optical system to be positioned between two optical axes of the pair of viewing optical systems.
The first focusing mechanism can be a manual focusing knob, and the association mechanism can include a gear train for transferring rotation of the manual focusing knob to the second focusing mechanism.
The first focusing mechanism can further include a screw shaft coaxially engaged with the manual focusing knob, and the release mechanism can include a disengaging mechanism for temporarily disengaging the manual focusing knob from the screw shaft without disengaging the manual focusing knob from the gear train.
The present disclosure relates to subject matter contained in Japanese Patent Application No. 2001-301872 (filed on Sep. 28, 2001) which is expressly incorporated herein in its entirety.